ospf6d : Intra area route for connected prefix not installed

Issue: When ospfv3 is configured on interface between routers in different network,
       the intra area route for the remote connected prefix is not installed in ospf
       route table and zebra

Fix: When the advertising router is directly connected but in different network
     the interface lookup in the intra area lsa processing does not provide
     the matching interface and valid nexthop. Therefore the nexthop is
     copied from the link state entry which contains valid
     ifindex required for installing the route.

Signed-off-by: kssoman <somanks@gmail.com>

ospf6d/ospf6_intra.c

@@ -1368,7 +1368,7 @@ void ospf6_intra_prefix_route_ecmp_path(struct ospf6_area *oa,
 	struct ospf6_nexthop *nh, *rnh;
 	char buf[PREFIX2STR_BUFFER];
 	bool route_found = false;
-	struct interface *ifp;
+	struct interface *ifp = NULL;
 	struct ospf6_lsa *lsa;
 	struct ospf6_intra_prefix_lsa *intra_prefix_lsa;
 
@@ -1571,12 +1571,15 @@ void ospf6_intra_prefix_route_ecmp_path(struct ospf6_area *oa,
 					ifp = if_lookup_prefix(
 						&old_route->prefix,
 						oa->ospf6->vrf_id);
-					if (ifp)
-						ospf6_route_add_nexthop(
-								old_route,
+				}
+
+				if (ifp) {
+					/* Nexthop interafce found */
+					ospf6_route_add_nexthop(old_route,
 								ifp->ifindex,
 								NULL);
 				} else {
+					/* Copy nexthops from ls entry */
 					ospf6_route_merge_nexthops(old_route,
 								   ls_entry);
 				}
@@ -1626,7 +1629,7 @@ void ospf6_intra_prefix_lsa_add(struct ospf6_lsa *lsa)
 	struct ospf6_prefix *op;
 	char *start, *current, *end;
 	char buf[PREFIX2STR_BUFFER];
-	struct interface *ifp;
+	struct interface *ifp = NULL;
 	int direct_connect = 0;
 	struct ospf6_path *path;
 
@@ -1716,10 +1719,13 @@ void ospf6_intra_prefix_lsa_add(struct ospf6_lsa *lsa)
 		if (direct_connect) {
 			ifp = if_lookup_prefix(&route->prefix,
 					       oa->ospf6->vrf_id);
-			if (ifp)
-				ospf6_route_add_nexthop(route, ifp->ifindex,
-							NULL);
+		}
+
+		if (ifp) {
+			/* Nexthop interface found */
+			ospf6_route_add_nexthop(route, ifp->ifindex, NULL);
 		} else {
+			/* Copy nexthops from ls entry */
 			ospf6_route_copy_nexthops(route, ls_entry);
 		}